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-rw-r--r--drivers/dahdi/dahdi-base.c96
1 files changed, 75 insertions, 21 deletions
diff --git a/drivers/dahdi/dahdi-base.c b/drivers/dahdi/dahdi-base.c
index 90d6841..a1ecb8a 100644
--- a/drivers/dahdi/dahdi-base.c
+++ b/drivers/dahdi/dahdi-base.c
@@ -427,9 +427,30 @@ static inline struct dahdi_chan *chan_from_file(struct file *file)
file->private_data : chan_from_num(UNIT(file));
}
-static struct dahdi_span *find_span(int spanno)
+/**
+ * span_find_and_get() - Search for the span by number, and if found take out
+ * a reference on it.
+ *
+ * When you are no longer using the returned pointer, you must release it with
+ * a put_span call.
+ *
+ */
+static struct dahdi_span *span_find_and_get(int spanno)
{
- return (spanno > 0 && spanno < DAHDI_MAX_SPANS) ? spans[spanno] : NULL;
+ unsigned long flags;
+ struct dahdi_span *span;
+
+ spin_lock_irqsave(&chan_lock, flags);
+ span = (spanno > 0 && spanno < DAHDI_MAX_SPANS) ? spans[spanno] : NULL;
+ if (likely(span && !try_module_get(span->ops->owner)))
+ span = NULL;
+ spin_unlock_irqrestore(&chan_lock, flags);
+ return span;
+}
+
+static void put_span(struct dahdi_span *span)
+{
+ module_put(span->ops->owner);
}
static inline unsigned int span_count(void)
@@ -699,7 +720,7 @@ static int dahdi_proc_read(char *page, char **start, off_t off, int count, int *
if (!spanno)
return 0;
- s = find_span(spanno);
+ s = span_find_and_get(spanno);
if (!s)
return -ENODEV;
@@ -834,6 +855,8 @@ static int dahdi_proc_read(char *page, char **start, off_t off, int count, int *
*eof = 1;
if (len > count)
len = count; /* don't return bytes not asked for */
+
+ put_span(s);
return len;
}
#endif
@@ -3895,10 +3918,12 @@ static int dahdi_ioctl_setparams(struct file *file, unsigned long data)
*/
static int dahdi_ioctl_spanstat(struct file *file, unsigned long data)
{
+ int ret = 0;
struct dahdi_spaninfo spaninfo;
struct dahdi_span *s;
int j;
size_t size_to_copy;
+ bool via_chan = false;
size_to_copy = sizeof(struct dahdi_spaninfo);
if (copy_from_user(&spaninfo, (void __user *)data, size_to_copy))
@@ -3909,8 +3934,9 @@ static int dahdi_ioctl_spanstat(struct file *file, unsigned long data)
return -EINVAL;
s = chan->span;
+ via_chan = true;
} else {
- s = find_span(spaninfo.spanno);
+ s = span_find_and_get(spaninfo.spanno);
}
if (!s)
return -EINVAL;
@@ -3963,8 +3989,12 @@ static int dahdi_ioctl_spanstat(struct file *file, unsigned long data)
}
if (copy_to_user((void __user *)data, &spaninfo, size_to_copy))
- return -EFAULT;
- return 0;
+ ret = -EFAULT;
+
+ if (!via_chan)
+ put_span(s);
+
+ return ret;
}
/**
@@ -3973,9 +4003,11 @@ static int dahdi_ioctl_spanstat(struct file *file, unsigned long data)
*/
static int dahdi_ioctl_spanstat_v1(struct file *file, unsigned long data)
{
+ int ret = 0;
struct dahdi_spaninfo_v1 spaninfo_v1;
struct dahdi_span *s;
int j;
+ bool via_chan = false;
if (copy_from_user(&spaninfo_v1, (void __user *)data,
sizeof(spaninfo_v1))) {
@@ -3988,8 +4020,9 @@ static int dahdi_ioctl_spanstat_v1(struct file *file, unsigned long data)
return -EINVAL;
s = chan->span;
+ via_chan = true;
} else {
- s = find_span(spaninfo_v1.spanno);
+ s = span_find_and_get(spaninfo_v1.spanno);
}
if (!s)
@@ -4051,9 +4084,11 @@ static int dahdi_ioctl_spanstat_v1(struct file *file, unsigned long data)
if (copy_to_user((void __user *)data, &spaninfo_v1,
sizeof(spaninfo_v1))) {
- return -EFAULT;
+ ret = -EFAULT;
}
- return 0;
+ if (!via_chan)
+ put_span(s);
+ return ret;
}
static int dahdi_common_ioctl(struct file *file, unsigned int cmd,
@@ -4389,33 +4424,40 @@ static int dahdi_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long da
struct dahdi_lineconfig lc;
struct dahdi_span *s;
+ res = 0;
if (copy_from_user(&lc, (void __user *)data, sizeof(lc)))
return -EFAULT;
- s = find_span(lc.span);
+ s = span_find_and_get(lc.span);
if (!s)
return -ENXIO;
+
if ((lc.lineconfig & 0x1ff0 & s->linecompat) !=
- (lc.lineconfig & 0x1ff0))
+ (lc.lineconfig & 0x1ff0)) {
+ put_span(s);
return -EINVAL;
+ }
if (s->ops->spanconfig) {
s->lineconfig = lc.lineconfig;
s->lbo = lc.lbo;
s->txlevel = lc.lbo;
s->rxlevel = 0;
- return s->ops->spanconfig(s, &lc);
+ res = s->ops->spanconfig(s, &lc);
}
- return 0;
+ put_span(s);
+ return res;
}
case DAHDI_STARTUP:
if (get_user(j, (int __user *)data))
return -EFAULT;
- s = find_span(j);
+ s = span_find_and_get(j);
if (!s)
return -ENXIO;
- if (s->flags & DAHDI_FLAG_RUNNING)
+ if (s->flags & DAHDI_FLAG_RUNNING) {
+ put_span(s);
return 0;
+ }
if (s->ops->startup)
res = s->ops->startup(s);
@@ -4440,11 +4482,12 @@ static int dahdi_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long da
s->chans[x]->rxhooksig = DAHDI_RXSIG_INITIAL;
}
}
+ put_span(s);
return 0;
case DAHDI_SHUTDOWN:
if (get_user(j, (int __user *)data))
return -EFAULT;
- s = find_span(j);
+ s = span_find_and_get(j);
if (!s)
return -ENXIO;
@@ -4455,6 +4498,7 @@ static int dahdi_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long da
if (s->ops->shutdown)
res = s->ops->shutdown(s);
s->flags &= ~DAHDI_FLAG_RUNNING;
+ put_span(s);
return 0;
case DAHDI_ATTACH_ECHOCAN:
{
@@ -4628,11 +4672,13 @@ static int dahdi_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long da
/* get struct from user */
if (copy_from_user(&maint, (void __user *)data, sizeof(maint)))
return -EFAULT;
- s = find_span(maint.spanno);
+ s = span_find_and_get(maint.spanno);
if (!s)
return -EINVAL;
- if (!s->ops->maint)
+ if (!s->ops->maint) {
+ put_span(s);
return -ENOSYS;
+ }
spin_lock_irqsave(&s->lock, flags);
/* save current maint state */
i = s->maintstat;
@@ -4648,8 +4694,10 @@ static int dahdi_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long da
break;
rv = s->ops->maint(s, maint.command);
spin_unlock_irqrestore(&s->lock, flags);
- if (rv)
+ if (rv) {
+ put_span(s);
return rv;
+ }
spin_lock_irqsave(&s->lock, flags);
break;
case DAHDI_MAINT_LOOPUP:
@@ -4657,8 +4705,10 @@ static int dahdi_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long da
s->mainttimer = DAHDI_LOOPCODE_TIME * DAHDI_CHUNKSIZE;
rv = s->ops->maint(s, maint.command);
spin_unlock_irqrestore(&s->lock, flags);
- if (rv)
+ if (rv) {
+ put_span(s);
return rv;
+ }
spin_lock_irqsave(&s->lock, flags);
break;
case DAHDI_MAINT_FAS_DEFECT:
@@ -4678,8 +4728,10 @@ static int dahdi_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long da
rv = s->ops->maint(s, maint.command);
spin_unlock_irqrestore(&s->lock, flags);
- if (rv)
+ if (rv) {
+ put_span(s);
return rv;
+ }
spin_lock_irqsave(&s->lock, flags);
break;
default:
@@ -4687,10 +4739,12 @@ static int dahdi_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long da
module_printk(KERN_NOTICE,
"Unknown maintenance event: %d\n",
maint.command);
+ put_span(s);
return -ENOSYS;
}
dahdi_alarm_notify(s); /* process alarm-related events */
spin_unlock_irqrestore(&s->lock, flags);
+ put_span(s);
break;
}
case DAHDI_DYNAMIC_CREATE:
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-29 13:23:39 +0000